[Prevention of second primary cancer with vitamin supplementation in patients treated for head and neck cancers].

Second primary cancers often occur in head and neck cancer patients successfully treated by radiation therapy. Experimental and epidemiological data suggest that these second primaries might be prevented by antioxidant vitamins, in particular beta-carotene and alpha-tocopherol. A randomized double-blind clinical trial is being conducted in Canada to determine whether vitamin supplementation with beta-carotene (30 mg/d) and alpha-tocopherol (400 IU/d) reduces the incidence of second primaries in head and neck cancer patients treated by radiation therapy.